CT-ALEXION-PHARMA

Alexion Pharmaceuticals, Inc. (NASDAQ:ALXN) announced today that Japan’s
Ministry of Health, Labour and Welfare (MHLW) has approved Kanuma®
(sebelipase alfa) for the treatment of patients of all ages in Japan
with lysosomal acid lipase deficiency (LAL-D). Kanuma, an innovative
enzyme replacement therapy (ERT), is the first therapy approved in Japan
for the treatment of patients with LAL-D, a genetic and progressive
ultra-rare metabolic disease in which patients suffer multi-organ damage
and premature death. Alexion expects that initial patients with LAL-D in
Japan will start commercial treatment with Kanuma in Q3 2016.

“We are gratified that patients of all ages in Japan who suffer from
LAL-D will now have the first approved therapy that addresses the
underlying cause of this devastating disease,” said David Hallal, Chief
Executive Officer of Alexion. “Importantly, the label notes the
significant survival benefit in infants with LAL-D who were treated with
Kanuma, as well as reductions in important markers of liver disease and
significant improvements in lipid parameters in pediatric and adult
patients. We look forward to working with healthcare authorities to
bring Kanuma to patients with LAL-D and their physicians in Japan as
quickly as possible.”

LAL-D is a genetic, chronic, and progressive metabolic disease
associated with significant morbidity and premature mortality.1
It is an ultra-rare disease, which is defined as a disease that affects
fewer than 20 patients per one million of the general population.2
Patients with LAL-D can experience a rapid onset of life-threatening
disease manifestations, and without treatment, the youngest patients
with LAL-D face rapid disease progression that is typically fatal within
a matter of months. In addition, similar to other liver diseases, many
patients may be asymptomatic until they experience a severe consequence
of the disease. LAL-D is caused by genetic mutations that result in a
marked decrease or loss in vital LAL enzyme activity in the lysosomes
across multiple body tissues, leading to the chronic build-up of
cholesteryl esters and triglycerides in the liver, blood vessel walls,
and other organs.1,3

“I am very pleased that Kanuma has been approved in Japan for the
treatment of patients with LAL-D, a devastating ultra-rare disease for
which there have previously been no effective or approved treatments.
Unfortunately, many children and adults with LAL-D are undiagnosed or
misdiagnosed for many years, and suffer progressive organ damage leading
to severe and life-threatening outcomes,” said Dr. Yoshikatsu Eto,
Director at Advanced Clinical Research Center & Asian LSD Center,
Institute of Neurological Disorders. “Today’s approval of Kanuma is a
momentous occasion for patients with LAL-D, their families, and the
medical community in Japan, which now has the first approved treatment
to replace the deficient LAL enzyme and address the life-threatening
manifestations of this disease.”

Kanuma is also approved for the treatment of patients with LAL-D in the
United States and European Union.

Clinical Data4

The approval of Kanuma in Japan was based on data from two clinical
studies and a supporting open-label extension study comprising infant,
pediatric, and adult patients with LAL-D, including two Japanese
patients. Study results showed significant benefit in terms of survival
beyond 12 months (67%, or 6 out of 9) in non-Japanese patients with
rapidly progressive disease presenting from infancy, compared with an
untreated historical control in which no survival over 8 months after
birth was reported. In pediatric and adult patients with LAL-D (ages 4
to 58 years), treatment with Kanuma was associated with a significantly
greater proportion of patients achieving ALT normalization compared with
placebo (31 percent vs. 7 percent, p=0.0271). Treatment with Kanuma also
resulted in larger reductions from baseline in liver fat content
compared to treatment with placebo. In addition, treated patients had
significant improvements in lipid parameters, including LDL-C, HDL-C,
non-HDL-C, and triglycerides, compared to placebo. Continued
improvements in ALT, LDL-C and HDL-C were seen in patients treated with
Kanuma beyond 20 weeks.

The most commonly reported adverse events observed in Japanese and
non-Japanese patients in clinical studies included pyrexia, abdominal
pain, diarrhea, urticaria, and vomiting. Urticaria was reported in two
Japanese patients.

About Lysosomal Acid Lipase Deficiency (LAL-D)

LAL-D is a genetic, chronic, and progressive ultra-rare metabolic
disease associated with significant morbidity and premature mortality.
In patients with LAL-D, genetic mutations result in a marked decrease or
loss in activity of the vital LAL enzyme. This leads to marked
accumulation of cholesteryl esters and triglycerides in vital organs,
blood vessels, and other tissues, resulting in progressive and
multi-organ damage including fibrosis, cirrhosis, liver failure,
accelerated atherosclerosis, cardiovascular disease, and other
devastating consequences.1,3

LAL-D affects patients of all ages with clinical manifestations from
infancy through adulthood and may have sudden and unpredictable clinical
complications. Infants experience profound growth failure, liver
fibrosis, and cirrhosis, with a median age of death at 3.7 months.5
In an observational study, approximately 50% of children and adults with
LAL-D progressed to fibrosis, cirrhosis, or liver transplant in 3 years.6
The median age of onset of LAL-D is 5.8 years, and the disease can be
diagnosed with a simple blood test.7,8

About Kanuma® (sebelipase alfa)

Kanuma®
(sebelipase alfa) is an innovative enzyme
replacement therapy that addresses the underlying cause of lysosomal
acid lipase deficiency (LAL-D) by reducing substrate accumulation in the
lysosomes of cells throughout the body. In clinical studies, treatment
with Kanuma improved survival in infants with LAL-D and led to
significant reductions in ALT and liver fat content, as well as
significant improvements in lipid parameters, in children and adults
with LAL-D.

Kanuma is approved in the United States, European Union, and Japan.

IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS

Hypersensitivity reactions, including anaphylaxis, have been reported in
KANUMA-treated patients. In clinical trials, 3 of 106 (3%) patients
treated with KANUMA experienced signs and symptoms consistent with
anaphylaxis. These patients experienced reactions during infusion with
signs and symptoms including chest discomfort, conjunctival injection,
dyspnea, generalized and itchy rash, hyperemia, swelling of eyelids,
rhinorrhea, severe respiratory distress, tachycardia, tachypnea, and
urticaria. Anaphylaxis has occurred as early as the sixth infusion and
as late as 1 year after treatment initiation.

In clinical trials, 21 of 106 (20%) KANUMA-treated patients, including 9
of 14 (64%) infants and 12 of 92 (13%) pediatric patients, 4 years and
older, and adults experienced signs and symptoms either consistent with
or that may be related to a hypersensitivity reaction. Signs and
symptoms of hypersensitivity reactions, occurring in two or more
patients, included abdominal pain, agitation, fever, chills, diarrhea,
eczema, edema, hypertension, irritability, laryngeal edema, nausea,
pallor, pruritus, rash, and vomiting. The majority of reactions occurred
during or within 4 hours of the completion of the infusion. Patients
were not routinely pre-medicated prior to infusion of KANUMA in these
clinical trials.

Due to the potential for anaphylaxis, appropriate medical support should
be readily available when KANUMA is administered.

Hypersensitivity to Eggs or Egg Products: Consider the risks and
benefits of treatment in patients with known systemic hypersensitivity
reactions to eggs or egg products.

ADVERSE REACTIONS

The most common adverse reactions are: In patients with Rapidly
Progressive Disease Presenting within the First 6 Months of Life (≥30%):
diarrhea, vomiting, fever, rhinitis, anemia, cough, nasopharyngitis, and
urticaria. In pediatric and adult patients (≥8%): headache, fever,
oropharyngeal pain, nasopharyngitis, asthenia, constipation, and nausea.

About Alexion

Alexion is a global biopharmaceutical company focused on developing and
delivering life-transforming therapies for patients with devastating and
rare disorders. Alexion developed and commercializes Soliris®
(eculizumab), the first and only approved complement inhibitor to treat
patients with paroxysmal nocturnal hemoglobinuria (PNH) and atypical
hemolytic uremic syndrome (aHUS), two life-threatening ultra-rare
disorders. As the global leader in complement inhibition, Alexion is
strengthening and broadening its portfolio of complement inhibitors,
including evaluating potential indications for eculizumab in additional
severe and ultra-rare disorders. Alexion’s metabolic franchise includes
two highly innovative enzyme replacement therapies for patients with
life-threatening and ultra-rare disorders, Strensiq®
(asfotase alfa) to treat patients with hypophosphatasia (HPP) and Kanuma®
(sebelipase alfa) to treat patients with lysosomal acid lipase
deficiency (LAL-D). In addition, Alexion is advancing the most robust
rare disease pipeline in the biotech industry, with highly innovative
product candidates in multiple therapeutic areas. This press release and
further information about Alexion can be found at: www.alexion.com
.

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Forward-Looking Statements

This news release contains forward-looking statements, including
statements related to potential medical benefits of Kanuma®
(sebelipase alfa) for lysosomal acid lipase deficiency (LAL-D).
Forward-looking statements are subject to factors that may cause
Alexion’s results and plans to differ from those expected, including,
for example, decisions of regulatory authorities regarding marketing
approval or material limitations on the marketing of Kanuma for LAL-D,
delays in arranging satisfactory manufacturing capabilities and
establishing commercial infrastructure for Kanuma for LAL-D, the
possibility that results of clinical trials are not predictive of safety
and efficacy results of Kanuma in broader or different patient
populations, the risk that third party payors (including governmental
agencies) will not reimburse for the use of Kanuma at acceptable rates
or at all, the risk that estimates regarding the number of patients with
Kanuma and observations regarding the natural history of patients with
Kanuma are inaccurate, and a variety of other risks set forth from time
to time in Alexion's filings with the Securities and Exchange
Commission, including but not limited to the risks discussed in
Alexion's Annual Report on Form 10-K for the period ended December 31,
2015 and in Alexion's other filings with the SEC. Alexion does not
intend to update any of these forward-looking statements to reflect
events or circumstances after the date hereof, except when a duty arises
under law.